The literature focused on substance abuse and dependence rather than on substance use per se. Findings show there has been a recent sharp resurgence in adolescent drug use. Biological factors, including genetic and temperament characteristics, as well as family environmental factors, are emerging as important etiological variables. Comorbidity with other psychiatric disorders, particularly with conduct disorders, is frequent and complicates treatment. New assessment instruments are available for clinical and research use. Among treatment modalities, family-based interventions have received the most study. Overall, the past decade has seen growth in the volume and sophistication of research on adolescent substance abuse and in the conceptualization of this problem. Further research is needed, particularly on the significance of comorbid conditions, individualized and effective treatment approaches, further testing and refinement of nosological systems for categorizing adolescent drug-use disorders, interventions targeted to high-risk groups and individuals, and barriers to implementation of effective preventive interventions. 4 tables and 93 references